This invention is generally in the field of ophthalmic therapies, and more particularly to the use of a microneedle for infusion of a fluid drug formulation into ocular tissues for targeted, local drug delivery.
The delivery of drug to the eye is extremely difficult, particularly delivery of macromolecules and delivery to the posterior segment. Many inflammatory and proliferative diseases in the posterior region of the eye require long term pharmacological treatment. Examples of such diseases include macular degeneration, diabetic retinopathy, and uveitis. In addition, many choroidal maladies that are associated with inflammatory responses, proliferation, and neovascularization require long term pharmacological treatment. It is difficult to deliver effective doses of drug to the posterior segment using conventional delivery methods such as topical application, which has poor efficacy, and systemic administration, which often causes significant side effects, and often does not reach the site of infection. (Geroski & Edelhauser, Invest. Ophthalmol. Vis. Sci. 41:961-64 (2000)). For example, while eye drops are useful in treating conditions affecting the exterior surface of the eye or tissue(s) at the front of the eye, the eye drops cannot significantly penetrate the eye, as may be required for the treatment of various retinal diseases and choroidal maladies.
Direct injection into the eye, using conventional needles and syringes has been reported to be effective, but requires professional training and raises concerns about safety (Maurice, J. Ocul. Pharmacol. Ther. 17:393-401 (2001)). It also would be desirable to be able to minimize the number and/or frequency of eye injection treatments needed to deliver therapeutically effective amounts of drug to the ocular tissue sites that need it.
The suprachoroidal space (SCS) of the eye has been studied, and its cannulation described as a possible route for drug delivery. See, e.g., Olsen, et al., American J. Ophthalmology 142(5): 777-87 (Nov. 2006).; PCT Patent Application Publication No. WO 2007/100745.
It therefore would be desirable to provide better, safer, more effective techniques for the direct delivery of therapeutic agents to posterior segment eye tissues, for example, to treat a posterior ocular disorder. It further would be desirable to provide better, safer, more effective techniques for the direct delivery of therapeutic agents to the SCS for the treatment of choroidal maladies, for example, choroidal maladies associated with vascular abnormalities. The present invention addresses these and other needs.